一株氯嘧磺隆降解菌分离鉴定及降解条件优化

为解决氯嘧磺隆残留对土壤、水体污染及后茬敏感作物药害问题,为污染土壤微生物修复提供降解菌种资源,文中采用富集培养、逐级驯化等方法,从氯嘧磺隆污染土壤中分离到1株高效氯嘧磺隆降解菌T9DB-01,经形态特征、生理生化及16S rDNA序列分析,鉴定为假单胞菌Pseudomonas sp.。采用单因素实验探究温度、pH值、底物浓度、装液量和接种量对菌株T9DB-01降解氯嘧磺隆的影响,采用正交试验及验证,优化菌株T9DB-01对氯嘧磺隆降解条件。结果表明,在30℃,pH 8.0,底物浓度200 mg/L,装液量100 mL/250 mL,接种量4%的条件下,5 d后降解率达到93.7%。该降解菌株对氯嘧磺隆污染土壤原位生物修复具有一定的应用潜力。     

Production of Factor VIII by Human Liver Sinusoidal Endothelial Cells Transplanted in Immunodeficient uPA Mice

Liver sinusoidal endothelial cells (LSECs) form a semi-permeable barrier between parenchymal hepatocytes and the blood. LSECs participate in liver metabolism, clearance of pathological agents, immunological responses, architectural maintenance of the liver and synthesis of growth factors and cytokines. LSECs also play an important role in coagulation through the synthesis of Factor VIII (FVIII). Herein, we phenotypically define human LSECs isolated from fetal liver using flow cytometry and immunofluorescence microscopy. Isolated LSECs were cultured and shown to express endothelial markers and markers specific for the LSEC lineage. LSECs were also shown to engraft the liver when human fetal liver cells were transplanted into immunodeficient mice with liver specific expression of the urokinase-type plasminogen activator (uPA) transgene (uPA-NOG mice). Engrafted cells expressed human Factor VIII at levels approaching those found in human plasma. We also demonstrate engraftment of adult LSECs, as well as hepatocytes, transplanted into uPA-NOG mice. We propose that overexpression of uPA provides beneficial conditions for LSEC engraftment due to elevated expression of the angiogenic cytokine, vascular endothelial growth factor. This work provides a detailed characterization of human midgestation LSECs, thereby providing the means for their purification and culture based on their expression of CD14 and CD32 as well as a lack of CD45 expression. The uPA-NOG mouse is shown to be a permissive host for human LSECs and adult hepatocytes, but not fetal hepatoblasts. Thus, these mice provide a useful model system to study these cell types in vivo. Demonstration of human FVIII production by transplanted LSECs encourages further pursuit of LSEC transplantation as a cellular therapy for the treatment of hemophilia A.     

Inhibition of chemical dose in biological phosphorus and nitrogen removal in simultaneous chemical precipitation for phosphorus removal

A study on the influence of chemical dosing on biological phosphorus and nitrogen removal was carried out through batch experimental tests by lab-scale and a full-scale wastewater treatment plant (employing a typical anaerobic-anoxic-oxic treatment). Results indicated that the inhibition of aluminum salt on biological phosphorus release and uptake processes is significant, as well as the inhibition of aluminum salt on Ammonia-Oxidizing Bacteria (AOB) is dominantly observed in the nitrification process and is recoverability. The inhibition of iron salt in biological phosphorus and nitrogen removal is weak, and only the inhibition of iron salt on phosphorus release at anaerobic periods emerge under large dosing. Evidence shows persistent inhibition from the accumulation of chemical doses in sludge mass. Intermittent chemical dosing proves recommendable for simultaneous chemical phosphorus removal.     

No evidence of murine leukemia virus-related viruses in live attenuated human vaccines

Background

The association of xenotropic murine leukemia virus (MLV)-related virus (XMRV) in prostate cancer and chronic fatigue syndrome reported in previous studies remains controversial as these results have been questioned by recent data. Nonetheless, concerns have been raised regarding contamination of human vaccines as a possible source of introduction of XMRV and MLV into human populations. To address this possibility, we tested eight live attenuated human vaccines using generic PCR for XMRV and MLV sequences. Viral metagenomics using deep sequencing was also done to identify the possibility of other adventitious agents.

Results

All eight live attenuated vaccines, including Japanese encephalitis virus (JEV) (SA-14-14-2), varicella (Varivax), measles, mumps, and rubella (MMR-II), measles (Attenuvax), rubella (Meruvax-II), rotavirus (Rotateq and Rotarix), and yellow fever virus were negative for XMRV and highly related MLV sequences. However, residual hamster DNA, but not RNA, containing novel endogenous gammaretrovirus sequences was detected in the JEV vaccine using PCR. Metagenomics analysis did not detect any adventitious viral sequences of public health concern. Intracisternal A particle sequences closest to those present in Syrian hamsters and not mice were also detected in the JEV SA-14-14-2 vaccine. Combined, these results are consistent with the production of the JEV vaccine in Syrian hamster cells.

Conclusions

We found no evidence of XMRV and MLV in eight live attenuated human vaccines further supporting the safety of these vaccines. Our findings suggest that vaccines are an unlikely source of XMRV and MLV exposure in humans and are consistent with the mounting evidence on the absence of these viruses in humans.     

3D Cube‐Maze‐Like Li‐Rich Layered Cathodes Assembled from 2D Porous Nanosheets for Enhanced Cycle Stability and Rate Capability of Lithium‐Ion Batteries

Li‐rich oxide is a promising candidate for the cathodes of next‐generation lithium‐ion batteries. However, its utilization is restricted by cycling instability and inferior rate capability. To tackle these issues, three‐dimensional (3D), hierarchical, cube‐maze‐like Li‐rich cathodes assembled from two‐dimensional (2D), thin nanosheets with exposed {010} active planes, are developed by a facile hydrothermal approach. Benefiting from their unique architecture, 3D cube‐maze‐like cathodes demonstrate a superior reversible capacity (285.3 mAh g^?1 at 0.1 C, 133.4 mAh g^?1 at 20.0 C) and a great cycle stability (capacity retention of 87.4% after 400 cycles at 2.0 C, 85.2% after 600 cycles and 75.0% after 1200 cycles at 20.0 C). When this material is matched with a graphite anode, the full cell achieves a remarkable discharge capacity (275.2 mAh g^?1 at 0.1 C) and stable cycling behavior (capacity retention of 88.7% after 100 cycles at 5.0 C, capacity retention of 84.8% after 100 cycles at 20.0 C). The present work proposes an accessible way to construct 3D hierarchical architecture assembled from 2D nanosheets with exposed high‐energy active {010} planes and verifies its validity for advanced Li‐rich cathodes.     

Histone H3 interacts and colocalizes with the nuclear shuttle protein and the movement protein of a geminivirus

Geminiviruses are plant-infecting viruses with small circular single-stranded DNA genomes. These viruses utilize nuclear shuttle proteins (NSPs) and movement proteins (MPs) for trafficking of infectious DNA through the nuclear pore complex and plasmodesmata, respectively. Here, a biochemical approach was used to identify host factors interacting with the NSP and MP of the geminivirus Bean dwarf mosaic virus (BDMV). Based on these studies, we identified and characterized a host nucleoprotein, histone H3, which interacts with both the NSP and MP. The specific nature of the interaction of histone H3 with these viral proteins was established by gel overlay and in vitro and in vivo coimmunoprecipitation (co-IP) assays. The NSP and MP interaction domains were mapped to the N-terminal region of histone H3. These experiments also revealed a direct interaction between the BDMV NSP and MP, as well as interactions between histone H3 and the capsid proteins of various geminiviruses. Transient-expression assays revealed the colocalization of histone H3 and NSP in the nucleus and nucleolus and of histone H3 and MP in the cell periphery and plasmodesmata. Finally, using in vivo co-IP assays with a Myc-tagged histone H3, a complex composed of histone H3, NSP, MP, and viral DNA was recovered. Taken together, these findings implicate the host factor histone H3 in the process by which an infectious geminiviral DNA complex forms within the nucleus for export to the cell periphery and cell-to-cell movement through plasmodesmata.     

No evidence for XMRV nucleic acids, infectious virus or anti-XMRV antibodies in Canadian patients with chronic fatigue syndrome

The gammaretroviruses xenotropic murine leukemia virus (MLV)-related virus (XMRV) and MLV have been reported to be more prevalent in plasma and peripheral blood mononuclear cells of chronic fatigue syndrome (CFS) patients than in healthy controls. Here, we report the complex analysis of whole blood and plasma samples from 58 CFS patients and 57 controls from Canada for the presence of XMRV/MLV nucleic acids, infectious virus, and XMRV/MLV-specific antibodies. Multiple techniques were employed, including nested and qRT-PCR, cell culture, and immunoblotting. We found no evidence of XMRV or MLV in humans and conclude that CFS is not associated with these gammaretroviruses.     

A strategy can be used to analyze intracellular interaction proteomics of cell-surface receptors

Comprehensive knowledge of the intracellular protein interactions of cell-surface receptors will greatly advance our comprehension of the underlying trafficking mechanisms. Hence, development of effective and high-throughput approaches is highly desired. In this work, we presented a strategy aiming to tailor toward the analysis of intracellular protein interactome of cell-surface receptors. We used α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors subunit GluA1 as an example to illustrate the methodological application. To capture intracellular proteins that interact with GluA1, after surface biotinylation of the prepared hippocampal neurons and slices, the non-biotinylated protein components as intracellular protein-enriched fraction were unconventionally applied for the following co-immunoprecipitation. The co-immuno-precipitated proteins were then analyzed through mass spectrometry-based proteomics and bioinformatics platforms. The detailed localizations indicated that intracellular proteins accounted for up to 93.7 and 90.3% of the analyzed proteins in the neurons and slices, respectively, suggesting that our protein preparation was highly effective to characterize intracellular interactome of GluA1. Further, we systematically revealed the protein functional profile of GluA1 intracellular interactome, thereby providing complete overview and better comprehension of diverse intracellular biological processes correlated with the complex GluA1 trafficking. All experimental results demonstrated that our methodology would be applicable and useful for intracellular interaction proteomics of general cell-surface receptors.